Catch Python exception and save traceback text as string

Question

I'm trying to write a nice error handler for my code, so that when it fails, the logs, traceback and other relevant info get emailed to me.

I can't figure out how to take an exception object and extract the traceback.

I find the traceback module pretty confusing, mostly because it doesn't deal with exceptions at all. It just fetches some global variables from somewhere, assuming that I want the most recent exception. But what if I don't? What if I want to ignore some exception in my error handler? (e.g. if I fail to send me email and want to retry.)

What I want

import traceback as tb

# some function that will fail after a few recursions
def myfunc(x):
   assert x > 0, "oh no"
   return myfunc(x-1)

try:
    myfunc(3)
except Exception as e:
    traceback_str = tb.something(e)

Note that tb.something takes e as an argument.

There's lots of questions on Stack Overflow about using the traceback module to get a traceback string. The unique thing about this question is how to get it from the caught exception, instead of global variables.

Result:

traceback_str contains the string:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 3, in myfunc
  File "<stdin>", line 3, in myfunc
  File "<stdin>", line 3, in myfunc
  File "<stdin>", line 2, in myfunc
AssertionError: oh no

Note that it contains not just the most recent function call, but the whole stack, and includes the "AssertionError" at the end

Answer 1

The correct function for tb.something(e) is

''.join(tb.format_exception(None, e, e.__traceback__))